ARC/eARC is definitely broken on this TV. This was one of the first issues I noticed with the QN90A. I get handshake dropouts and gotten the weird noise once, but the latter was only after the latest update. With eARC, I only get PCM, but the channels seem correct. With ARC, the channels aren't playing correctly. I've also noticed issues after having eARC on and switching from HDMI to live TV or apps. What's weird is that if I go into settings and Digital Audio Output setting in eARC, it shows DD+ for a second. I'm also noticing video drop-outs are back for me after the latest update. This seems symptomatic of software issues.Finding a soundbar or something for testing is a good idea. If only to help correctly lay blame on the amp or the TV. I don't think it's cables. I bought two new 2.1 cables for this and they both do it. Also, it happens every time I switch apps, which seems like more of a software thing. I'm only using regular ARC.
Pulling my amp remote out and switching away and back to the main input jars the system enough that they handshake and I get audio. I have to jiggle handles again, if I do anything to stop that audio.
I'm beginning to wonder if the crazy crack/shock sound is actually a bad buffer being fed to the audio hardware. Now that I can fix the audio myself without killing the power, I haven't been shutting it off with a bad audio channel state and I haven't been hearing the sound.
Hopefully I don't have to deal with this nonsense much longer. As soon as a new AppleTV drops I can avoid all these built in apps and go back to a nice easy setup.
Since I couldn't get my PC audio working right (and pass-through sounds poorer than a direct connection to me), I've had to bypass ARC/eARC and run my receiver as a second monitor at the cost of processing power to extend my displays. This mean I need to disable HDMI-CEC completely and lose the ability to output audio from apps, unless I want to constantly spend my life with this TV in the settings menu. Very frustrating.
After the latest update, I've had my remote fall asleep and re-pairing wouldn't fix the problem. The power button was the only responsive button. If I unplugged the TV and re-plugged it back in, the remote would work again. Motion settings also look 'off' for me on SD content. Any panning results in judder even with all Picture Clarity Setting maxed out. I'm also getting the settings getting lost issue. This last update has been terrible.It may start randomly turning off. That is what mine has progressed to. Last night while watching a baseball game, it turned off twice. I tried turning it on with the remote and nothing. I had to turn it on using button on tv and then had to re-pair the remote to the tv. Needless to say, the Mrs is not to happy with my purchase. 😄
I'm struggling with the same choice of whether to give the TV another chance. I'm on return #2 (for the dust issue and a dead pixel) and trying to decide if it's worth tolerating these issues for the price when there are so many great competitors being released this year.